Sheer curtains filter daylight and give you privacy during the day while keeping the room bright. Blockout curtains use a dense fabric, usually coated or hung with a separate lining, to cut the light right down and hold heat in or out.
What a sheer actually does
A sheer is a light, open weave fabric. Daylight comes through, the view out is softened rather than lost, and anyone looking in from the footpath sees a haze instead of your lounge room.
That only works in daylight. Once it is dark outside and the lights are on inside, a sheer gives you almost no privacy at all, which catches people out in ground floor front rooms.
Sheers also soften a hard room. A wall of glass and a tiled floor goes from echoey to comfortable once there is fabric across it, and the glare drops without the room going dim.
What blockout fabric is doing
Blockout comes in two forms. Some fabrics have a coating applied to the back in several passes, and others are a decorative face fabric hung with a separate blockout lining behind it.
A lined curtain usually hangs better and lasts longer, because the lining takes the sun and the face fabric stays out of it. It is heavier as well, so the track and the fixings have to be sized for it.
Blockout fabric on its own does not give you a dark room. Light comes around the sides, over the top and under the hem. Fixing that means a pelmet or a track that returns to the wall at each end, and enough length in the curtain.
Fullness is the number that decides how it looks
Fullness is how much fabric goes into the curtain compared to the width being covered. Most curtains are made at 2.0 to 2.5 times the track width, so a three metre track carries six to seven and a half metres of fabric across it.
Skinny curtains look skinny. If the folds flatten out once the curtain is drawn, it was made short on fullness, and no amount of dressing will fix it afterwards.
Sheers usually want to sit at the top of that range. The soft vertical folds are the whole point of a sheer, and they need enough fabric to form properly.
Running both on the one window
A double track puts sheers and blockouts on the same window, and this is the setup most people end up wanting in a living room or a main bedroom. Sheers closed through the day, blockouts across at night.
Order matters. The sheer normally runs on the track closest to the glass with the heavier curtain in front of it, though that can be reversed if you want the sheer to be the layer you see from the room.
Depth is the catch. A double track needs room in the reveal or space above the window, and a curtain in front of a sliding door needs somewhere to stack so it clears the opening properly.
Where each one earns its keep
Bedrooms are a blockout job, particularly for shift workers, small kids and any east facing window that gets the sun at six in the morning. Add a pelmet or a wall return if the room needs to be genuinely dark.
Living rooms usually get both layers. The sheer handles daytime privacy and glare, and the blockout deals with the western sun and the neighbours after dark.
West facing glass is worth treating from the outside. An awning or an external blind stops the sun before it reaches the window, and the curtain then only has the leftover heat to deal with. You can see the full sheer and blockout curtain range and compare it against roller blinds in sunscreen and blockout if fabric panels suit the room better.
Heat, and the gap behind the curtain
A curtain slows heat moving through a window by trapping air between the fabric and the glass. Gaps at the top and sides let that warm air spill into the room, which is why a pelmet or a ceiling mounted track makes more difference than the fabric choice alone.
Length helps too. A curtain that stops at the sill leaks around the bottom, and one that runs to the floor holds that air in place far better through a cold night.
If you are not sure whether a room wants sheers, blockouts or both, it is easier to decide with the fabrics held up against your own glass in your own light. Book a free measure and quote and we will bring the samples to you.
Common questions
Can you see through sheer curtains at night?
Yes. A sheer works on daytime light, so once it is dark outside and your lights are on, people can see in. Rooms facing a street or a footpath need a blockout layer or a blind behind the sheer for night privacy.
Do blockout curtains make a room completely dark?
Only if the light gaps are dealt with. The fabric stops light coming through, but light still comes around the sides, over the top and under the hem. A pelmet, a track that returns to the wall, and a longer drop are what get a room properly dark.
Can I have sheers and blockout curtains on the same window?
Yes, on a double track. The sheer normally sits closest to the glass with the blockout in front. You need enough depth in the reveal or above the window to carry both tracks, so it is worth checking before you order.